draw_pixels

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It only says 'Draw' which implies mutation but gives no details on overwriting behavior, coordinate system, alpha handling, or error conditions. This is a significant gap for a mutation tool without annotation support.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two short sentences with no redundant wording. It is front-loaded with the action and follows with a targeted use case, making it concise and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the simplicity of the tool and the rich schema (100% coverage), the description is mostly sufficient. It communicates the core action and a key use case. Minor gaps such as not explaining frame/layer targeting behavior are covered by the schema. Overall, it is complete enough for an agent to select and invoke the tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema provides 100% coverage of all parameters, including descriptions for frame, layer, and pixels. The description adds no parameter-specific information, so it does not exceed the baseline value provided by the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool draws individual pixels on the canvas, using the specific verb 'Draw' and resource 'pixels'. The phrase 'precise pixel-art placement' helps distinguish it from sibling shape tools like draw_rect or draw_line, so it fully clarifies purpose and differentiates.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear context by stating 'Use for precise pixel-art placement', implying it is for pixel-level control rather than shapes. However, it does not explicitly mention alternatives or when not to use it, so it stops short of full when/when-not guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.